1. Field of the Invention
This invention relates to a yarn finding device for a winder.
A bobbin produced on a spinning frame, particularly on a ring spinning frame, normally has, adjacent end turns of a yarn thereon, a so-called tail yarn wound in several turns on a tail or head portion thereof in order to prevent an end of the yarn from being released from the bobbin or from clinging to an end of a yarn on another bobbin when the bobbin is transported to a subsequent rewinding step.
When a spinning bobbin having such a tail yarn thereon is to be supplied to a subsequent next rewinding step, that is, to an automatic winder, it is once supplied to a yarn end readying apparatus on which the tail yarn is released from the spinning bobbin in preparation for subsequent automatic splicing of the yarn to another yarn, and is then supplied to a winding unit.
In a yarn end finding device of such a yarn end readying apparatus, when a tail yarn wound on a tail or head portion of a bobbin is to be released or removed, beginning and last ends of a yarn which was wound on the bobbin by a spinning frame may sometimes be turned with and cling to each other to such a degree that it is difficult to release the tail yarn from the bobbin. Or else, where a reinforcing annular metal member is fitted on one or each of opposite ends of a take-up tube of the bobbin, the tail yarn may enter a gap which may possibly appear between the metal member and the take-up tube so that it may be impossible to release the tail yarn from the bobbin unless compressed air is blown to the bobbin or the bobbin is placed within a suction air flow. In either case, finding of a yarn, end will fail.
2. Description of the Related Art
As a device which can prevent such failure in finding an end of a yarn, the present applicant already proposed a device which is disclosed in Japanese patent laid-open No. 60-213669. In the proposed device, a suction cutter in the form of a drum which rotates along a cylindrical inner peripheral face of a suction case has a large number of yarn sucking holes formed in an outer peripheral face thereof, whereby an end of a yarn which is sucked in through a yarn passing hole of the suction case and one of the holes of the suction cutter is compulsorily fed along a very small gap defined between the outer peripheral face of the suction cutter and the inner peripheral face of the suction case and is thus abutted with the outer peripheral face of the suction cutter so that it is cut off by a fixed blade securely mounted on the suction case.
In the proposed device described above, there is a problem that, if an end of a yarn in a lump having a thickness corresponding to that of several very heavy yarns is sucked and comes to a position of the fixed blade, they may not be cut or may pass by the fixed blade and be wrapped around a rotary shaft or otherwise cause the outer peripheral face of the suction cutter and a cutting edge of the fixed blade to be contacted with each other under pressure, which may result in damage to the cutting edge of the fixed blade so that the sharpness in cutting of the fixed blade may become blunt in a short period of time. Accordingly, the proposed device is not practical.